Am I only 1% likely to be my Dad's kid?

[wordassociationfootball]

Last night I mentioned affectionately to my sis that I was imagining both our (deceased) parents smiling at us, their blue eyes twinkling. Sis (my only sibling) said Dad had green eyes. I just checked photos and his eyes were definitely blue. I had an odd feeling come over me so Googled whether two blue-eyed parents could have a green eyed (me) kid. 1% possibility. Can anyone gentically savvy increase the odds or tell me what they'd do in my shoes?
Full disclosure: When my Dad died I discovered he'd told my sis he wasn't my dad. I shrugged it off at the time as I'm like him/look like him in some ways... I always thought so anyway. There's a ten year gap between big sis and me. Mum had several miscarriages and they were on the brink of adopting when a pregnancy (me) stuck. I know that my mum had been in love with the husband of a couple they knew.
.... Holy mack mack, I cant believe how in denial I've been for so long about this. Thoughts please!

My parents and 5 sisters all have brown eyes and I have blue.

For various genetic reasons I am 100% certain that my parents are my parents and my sisters are my sisters.

Eye colour can be weird, I wouldn’t read too much into it!

Also agree with others that green eyes can be ‘blue’ - my kids are all ‘blue’ but two bright blue and youngest son greeny blue and other son greyish blue.

I think the biggest concern here is that your Dad actually TOLD your sister he isn't your biological Father.
Surely no Father would say this if there's no truth behind it.
As others have suggested I'd have a dna to find out if my sister is 💯 biological. In the scheme of things, regardless of results, she will always be your sister anyway, but you'd have clarity and peace of mind. I'm not the type of person who could go to the grave never knowing the absolute truth, but some people prefer ignorant bliss. It's your call.

DH and I have blue eyes. Both our parents/grandparents/all biological aunts& uncles have blue eyes. Not a brown eyes person in any of our family trees anyone knows of. Yet, one of our kids has brown eyes, the others have blue eyes. I didn’t have an affair and our child is definitely biologically ours.

People saying their parents have different colour eyes to them, both parents have brown eyes and the child has blue are not really understating dominant vs recessive genes.

If there was only one gene form each parent for eye colour and blue was recessive and brown dominant, then two parents with brown eyes could have a baby with blue eyes, no issues.

But as you say, both your parents have blue eyes and you don't, so what is most likely?

I think the issue is that there are multiple genes for eye colour, not just one. So depending on how the blue and green manifest, maybe the exact shade of blue or green eyes that you and your dad have are possible with you being his biological daughter.

However, you have doubts for other reasons so I think a DNA test to see if your sister is your full sister might be worth a try. Of course you'd then need a DNA test between your sister and dad to confirm that he is her dad.

Many confusion here. As a recessive gene, two blue eyed normally can only have a blue eye baby, unless in exceptional circumstances.

Two brow eyed parents can have a blue eye baby if they have a blue eye recessive gene themselves. Both would need to have it and there is then a 25% chance.

The issue here is that 'green' doesn't really exist from a genetic perspective. So it's either a green shade of blue ( some have a grey shade of blue too) or a green shade if brown, or hazel.

I've got dark brown eyes, DH has blue and DS has green. I don't think eye colour is a reliable indicator of parentage, but the fact he told your sister he wasn't your dad is more concerning. A DNA test with your sister is the only way to know.

DH blue eyes. Mine brown. Our four kids - one brown eyes, one blue eyes, one green eyes, one grey eyes! DH had a green eyed mum, I had a grey eyed mum - it so often skips a generation or two.

My parents have got brown and blue eyes
I've got grey
Two sisters have brown
One has green
Two brothers have brown
One has blue

I don't think eye colour is a reliable indicator of parentage
A really it can be a descent indicator in the case of two blue eyed parents.

I will never forget being 11 year old and not much thinking of consequences then when a school friend and I was discussing this matter. She said that both her parents had blue eyes. She had very brown eyes. I laughed and told her she told her she must adopted. That prompted her asking her parents and the truth came out. It ended up being a traumatic time for her. I felt really bad afterwards when I realised it was t a laughing matter at all.

@IHeartGeneHunt, your brown eye parent will have inherited a recessive blue gene along the line (sometimes it can go back a few generations).

This means that you and all your siblings had a 50% chance of having blue eyes (grey likely a shade of blue, green one of the two depending on the shade).

I have blue eyes. My kids dad has brown eyes. His dad has blue eyes, so he had a recessive blue gene. Our children had 50/50 chance to have one colour or the other. The elder has grey eyes (shade a blue, used to be very blue as a child). The other has hazel eyes, green and very light brown (variant of brown).

His children will have a 50% chance of having blue eyes if the mother has blue eyes.

If the mother has brown eyes, the child will have 100% brown (or variant of it) if the mother has no blue recessive or 25% blue if they do have a blue recessive.

AFAIK the blue-eyed gene is recessive, but when two recessive genes meet (in the lottery of conception) they become dominant.

Maybe the green-eyed gene is similar. Green is certainly less common than blue, at least in the U.K.

@vivainsomnia Many confusion here. As a recessive gene, two blue eyed normally can only have a blue eye baby, unless in exceptional circumstances

what circumstances? Per my experience above, 2 blue eyed parents, blue eyes only in both family trees to great grandparent level (at minimum), and a brown eyed child who is definitely a biological child of both parents. Are you saying there must have been an affair at grandparent/great grandparent level with someone with brown eyes, yet all kids of that affair had blue eyes, and then the brown eyes came out down the line?

Eye colour is encoded for by more than one gene.

Unfortunately in school they still teach us eye colour is inherited in a dominant/recessive way when it isn't.

Normally other people particularly those not related to you can tell you if you are related. So it isn't rare for a child to look like one parent's close blood relation if the child doesn't look like either parent. However you have to see a few of that person's blood relations to see that....

It is possible for two blue eyed to have a brown eye maybe but I'd very rare, hence the 1%.

My two friends have brown eyes and thier son was blue eyed

That's a very simple model.

It assumes you only have 2 genes for colour, one from each parent. These are usually written as B for brown and b for blue.

B is dominant so if you have the genese Bb you will have brown eyes but you can pass on the b to your child. So if your brown eyed partner has Bb you can easily have a blue eyed child.

BUT there isn't just one gene for eye colour, instead of having BB, Bb, bb, or bB it's more like BbbBBbbB so there are many more possible combinations and this is where the green, grey and hazel.

So your eyes are a mix of colours but you only see the dominant one(s).

Think of it as looking through 8 pieces of glass on top of each other, if they are all blue then you will see blue, if a majority are brown you will see brown but with different combinations you might see gray, green, light blue, dark blue etc.

Added to the genetics are some genetic conditions, Waardenburg syndrome causes at least one blue eye, deafness and often white hair at the forelock.

This happens regardless of your family eye colour(s) so you get black people with bright blue eyes if they have Waardenburg.

https://www.thetech.org/ask-a-geneticist/articles/2004/ask2/

https://medlineplus.gov/genetics/understanding/traits/eyecolor/